Congo Puffers and CO2 Injected Planted Tank

[ware187]

Anyone have experience with Congo puffers and highly planted CO2 injected tanks? I have recently set up a medium to heavy planted 29 gal. tank and I am injecting CO2 and dosing fertilizers. It is a mostly Congo river themed biotope with African Water Fern(bolbitis heudelotti), Dwarf Lily (Nymphaea sp.), Crinum Calamistratum, Tiger Lotus(Nymphaea zenkeri), Anubias Barteri var. Nana, and Java Moss on a piece of drift wood, planted in Flourite black sand. Most of these are stem or bulb plants that grow tall, so will leave a good portion of the substrate available for a puffer to bury themselves in. I am interested in getting a Congo puffer, but had a few questions to see if this tank would be appropriate for a puffer. My concerns are about the substrate, pH fluctuations caused by CO2, and how sensitive puffers are to nitrAtes.

1. Is the Flourite black sand ok, or is it too sharp for their skin?

2. I currently have the CO2 injection controlled by a solenoid so it is on during an 8 hour photo period and off at night. CO2 is controlled by the same timers as the lights, but during the lights on period, the CO2 will cause my pH to drop from 7.6 to 6.6. Are puffers sensitive to such a pH shift? (KH is a consistent 4 and GH 7 - API test kits). My other option would be to keep the CO2 on all the time and this would keep the pH steady(would need to be careful during water changes). I also use a surface skimmer to keep proteins from filming the surface and to help balance O2/CO2 levels. CO2 at peak is ~30ppm, once tank is more mature want to reduce to ~20ppm for a safer fish buffer and less drastic pH shift.

3. And lastly, how sensitive are the puffers to nitrAtes, more specifically what are acceptable levels before puffers seem to be affected? Plants use nitrAtes and I may have to dose potassium nitrate occasionally if the plants use more nitrates than the bio-load can provide naturally. From what I have read Congo puffers are messy eaters, so I may not have to dose nitrogen at all, but if I have to, I want to do so in safe levels. (dosing ferts daily, so very small amounts to keep nitrAtes between 5-10ppm). I usually only dose with a nitrogen free solution since my tap has some nitrates, but don't want to shock the fish if I ever should have to add.

No puffer yet, but LFS has a coupe in stock. They can be hard to find and don't want to pass on the opportunity. If I decide to purchase, the puffer would be in a separate cycled 20 gal. until planted tank parameters are consistent and well established.

Sorry about the long post and any input would be greatly appreciated.

[Pufferpunk]

Considering they burrow 99% of the time, i'd think it would be uprooting a lot of plants. But you could leave an open area in the middle with sand.

[Biff Malawi]

As PP says adequate burial sites will be a concern. You can leave some space but you may need to adapt your aquascaping after the puffer decides where it wants to bury itself as knowing puffs they will probably not like the spot you choose.

I think the fluctuating Ph will be a problem, I believe that stable Ph is more important than what the Ph actually is. Leaving the Co2 on all the time may solve this but it has been my experience that leaving Co2 on during "lights out" when your plants are also giving off Co2 can cause problems. Admittedly I don't know the science behind it but that has been what I have learned in the past.

[RTR]

Question - do you realize that several of those plants are way too big for a 29 (the water lilies and the Crinum)? They require some time to establish or any burrowing fish will uproot them easily if not well establish before the fish goes in. I would suggest some serious re-thinking. The Crinum is magnificent as a centerpiece in a 50 or 75, but not with a digger fish. If you give the lilies enough light either will be cramped in a 29 alone. Both will go emerse.

FWIW

[eieio]

1. Is the Flourite black sand ok, or is it too sharp for their skin?

too sharp.......
Congo sand should be small rounded grains

[ware187]

Thanks for the comments everyone, I definitely have a few more things to consider.

RTR - I will reconsider putting a Congo puffer in with the Crimun, after reading further they don't like their roots to be disturbed at all. I actually gave the wrong size tank dimensions, I have a 30H (24x12x24), not much difference, but I'm thinking it should be deep enough, width is not ideal and it could be longer, but space in my apartment is an issue. Right now the Crimun is very small and they grow slow, so will see how it goes. The lilies are really just an experiment, I have really high nitrAtes from the tap(40-80ppm tested immediately and 20-40ppm after aging) and the lilies are said to be nutrient sponges. I'm trying to see if I can keep up pruning their growth in exchange for them bring nitrAtes to down an acceptable level, if they become too much I will remove. The dwarf is really small right now and the tiger is still just a bulb and has not sprouted.

Interesting article on OTS, do you think trumpet snails would help the substrate issue in planted OTS or are they too small, too few, to make a difference?

[RTR]

Crinums are not for any tank with a digger fish. Their roots are massive and closely packed (comparable to an Amazon sword plant, but will fill a 30XH in 2-3 years, effectively blocking the digger out. My emerse Crinums double the apparent substrate depth in about a year and a half to two years. They do not belong with any substrate-disturbing fish.

MTS are horrible pests, steer clear of them if at all possible. They are potentially dangerous for many puffers as their shell are too strong.

That water is not potable. Is that all you have available? It would be laborious and/or expensive to make it suitable for fish use. In the US, 30 ppm N is the legal limit for humans. Some fish are a bit sensitive for that much. I don't know the Congo's sensitivity. Pufferpunk has experience there, so may have more info on that fish.

FWIW...

[Stratters]

MTS are an absolute jeffing pain in the arse. It only took 2 of them a couple of months to reach biblical population levels

<bitter snail murderer>

[Pufferpunk]

They are potentially dangerous for many puffers as their shell are too strong.

Thing is though, I've never had a Congo that touched any snails. I had a fist-sized apple snail as a maid for mine for many years.

[RTR]

All those tasty, tender snorkels got ignored? That is amazing! Thanks for the info!